Drillstring swivel torque monitor

Abstract

Apparatus for rotationally locking the swivel of a drillstring during downhole backoff, directional drilling, and similar operations, and for continuous monitoring of the torque level in the drillstring. A first member has a collar which attaches to one side of the swivel, the collar having a main plate attached thereto and extending outwardly from the swivel. A second member is suspended from the plate, and has a set of jaws which can be closed to grip the swivel and thereby rotationally lock the swivel. A means for measuring forces between the first and second members is disposed between the first and second members, and in combination with appropriate processing and controls permits monitoring of torque on the drillstring while the drillstring is raised and lowered as desired.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This regular patent application claims priority to U.S. Provisional Patent Application Ser. No. 61 / 086,835, filed Aug. 7, 2008, for all purposes.BACKGROUND[0002]1. Field of the Invention[0003]This invention relates to apparatus used in connection with the drilling and servicing of boreholes in the earth, more particularly those frequently referred to as “wells,” such as oil and gas wells. More particularly, this invention relates to apparatus used in connection with the handling and manipulation of tubular strings, commonly referred to as drillstrings and workstrings.[0004]2. Related Art[0005]The drilling of earthen boreholes, namely “wells” (that term being used broadly, to include oil wells, gas wells, saltwater disposal wells, and any other type of earthen borehole), frequently involves the use of a long tubular string, often called a drillstring, which holds a drill bit at its lower end. The drill bit is rotated, either by rotation of...

AI Technical Summary

Benefits of technology

Enables safe and continuous monitoring of torque on drillstrings during raising and lowering, eliminating the risks associated with mechanical cables and allowing for precise torque application over extended distances without restricting movement.

Problems solved by technology

This task is complicated by the fact that the connection in question may be located many thousands of feet below the rig floor, by way of example 5,000′ to 10,000′ deep.

A further problem is that of monitoring the value of the torque on the drillstring during this operation.

While the drillstring could then be raised and lowered within the bounds of the length of the tong cable, it can be appreciated that this method carries a number of disadvantages, including:Limited distance that the drillstring can be raised—constrained by the length of the holdback line on the tongsRisk of injury to personnel, as this method creates a situation in which mechanical members with very high forces imposed on them are being moved about above the rig floor at heights which could result in serious injury or death if failure occurred.

Other disadvantages exist to this old method, but the safety aspect is one of the most important.

However, a disadvantage with known locking swivels is that when locked, and consequently some level of torque held in place on the drillstring, the amount of torque on the drillstring cannot be measured or monitored.

Images